LED Grow Light Glossary: Terms You Should Know

When you first enter the world of indoor growing, it can feel like learning a new language, especially when it comes to lighting. However, understanding the technology behind your setup is key to a successful harvest. Discover the terms you should know in this LED grow light glossary that will demystify the technical jargon and help you make the best decisions for your plants.

Chip on Board (COB)

COB technology involves attaching multiple LED chips to a substrate to form a single module. This creates a dense, powerful light source with intense canopy penetration. COB LEDs produce a very bright, uniform beam of light.

Color Rendering Index (CRI)

CRI indicates how accurately a light source reveals the true colors of an object compared to natural sunlight. Although not a primary metric for plant growth, a high CRI makes it easier for you to inspect your plants for signs of pests or nutrient deficiencies. It lets you see your plants in a more natural light.

Dimming

Another LED grow light term you should know is dimming, which refers to adjusting the intensity of your grow light. Growers often need to make adjustments during different growth stages. For example, delicate seedlings need gentle light, while mature plants in full flower require high-intensity light. Dimming also helps growers save energy when they do not need to run their grow lights at full power.

Diode

A diode is a semiconductor device that allows electric current to flow in one direction. In LED grow lights, these diodes emit light when electricity passes through them. The quality and type of diode significantly impact the light's efficiency, spectrum, and lifespan.

Driver

When we say “driver” in reference to grow lights, it has nothing to do with a car. Instead, this essential component regulates the power supplied to the LEDs.

It converts alternating current (AC) from your wall outlet to the direct current (DC) that the diodes need to operate. A high-quality driver ensures stable performance, protects the LEDs from power fluctuations, and improves the overall efficiency of the light fixture.

Efficacy

Efficacy measures how efficiently a grow light creates photosynthetically active radiation (PAR) from electrical energy. People usually express this in micromoles per joule (μmol/J). A higher efficacy rating means the light produces more usable light for every watt of electricity consumed, making it more cost-effective.

Footprint

The footprint is the effective coverage area that a grow light can illuminate. Manufacturers often provide two footprint measurements: one for the vegetative stage and a smaller one for the more light-intensive flowering stage. Matching your light's footprint to your grow space is essential for even growth.

Heat Sink

A heat sink is a component designed to dissipate heat away from the LED diodes. Overheating can reduce LED efficiency and shorten lifespan, so effective heat management is crucial. Grow lights use passive heat sinks (fins) or active ones (fans) to keep the fixture cool.

Infrared (IR) Light

IR light, particularly far-red light, is a wavelength just beyond the red part of the visible spectrum. It can help regulate plant development, including stem elongation and flowering cycles. Some full-spectrum lights include IR diodes to more closely mimic natural sunlight and enhance photosynthetic efficiency.

Kelvin

People use Kelvins for measuring a light source’s color temperature. Kelvin values on the low side tend to create a "warm" reddish light, ideal for the flowering stage. Higher Kelvin values produce a "cool" bluish light, which is excellent for vegetative growth.

Lumens

Lumens measure the total amount of visible light emitted by a source, based on what the human eye can see. This metric heavily weighs green and yellow light, but plants use both less efficiently than red and blue light.

PAR

PAR defines the range of the light spectrum that plants use for photosynthesis, typically between 400 and 700 nanometers. This measurement helps growers understand which portion of a light's output is actually useful for plant growth. PAR is a crucial metric for evaluating the effectiveness of a grow light.

Photosynthesis

Photosynthesis is the process plants use to convert light energy into chemical energy to fuel their growth. Chlorophyll, a green pigment in the leaves, absorbs the light that drives this vital function. Your grow light's job is to provide the specific light spectrum needed to maximize photosynthesis.

Photosynthetic Photon Flux

Photosynthetic photon flux measures the total amount of PAR light that a grow light fixture produces each second. It tells you the total light output of the fixture. This metric is important for comparing the raw power of different grow lights.

Photosynthetic Photon Flux Density

People use photosynthetic photon flux density to measure the intensity of usable light their plants receive. It is one of the most critical metrics for determining proper light placement and coverage.

Quantum Board

A quantum board is a large circuit board with hundreds of small to mid-sized LEDs spread across its surface. Its design provides excellent light distribution and efficiency, often using top-bin diodes. Quantum boards are a popular choice for home growers due to their even coverage and high performance.

Spectrum

Spectrum refers to the range of wavelengths of light that a grow light emits. Plants use different colors, or wavelengths, of light for various growth stages, such as blue light for vegetative growth and red light for flowering. A full-spectrum light mimics natural sunlight, providing all the wavelengths a plant needs throughout its life cycle.

Ultraviolet (UV) Light

UV light is a wavelength just outside the visible spectrum that can benefit plant growth in small, controlled amounts. It can trigger a plant's defense mechanisms, potentially increasing the production of oils and resins in plants like cannabis. However, excessive UV exposure can harm both plants and people.

Wattage

Wattage measures the amount of electrical power a grow light consumes. While higher wattage once correlated directly with more powerful lights, modern LEDs have changed this. Today, it is more a measure of energy use rather than a direct indicator of light output or growing potential.

Now that you have a better understanding of these terms, you can choose the perfect grow lights for your indoor vegetable garden. You can more confidently compare fixtures and find one that matches your specific needs.

LED Grow Lights Depot can help you take these next steps. Contact us today to learn more about our extensive collection of high-efficiency grow lights today so you can enjoy plentiful harvests.